Mostly Dry - This is a awesome hike. Go early !!!!! And when I say early I mean we rolled in at 5:30am am we got one of the last 4 parking spots. Well worth it. Most difficult part is the waterfall climb. It isn't hard but can be a little hairy if you don't like to climb up. This is a bottle neck, opens up at this point so the views are nice. When you get to the top of the falls it is a dramatic change in weather. Windy and colder. Before the climb is a good time to put in that extra layer you'll need it. Once you get to glass lake stay to the right along the lakes edge to get to Sky Pond. You can go off wandering but then you end up having to back track to find the trail. Once you reach the top it is breath taking.
If you want to hike additional trails such as mills lake and then Andrews glacier save them for the trip down. Save your energy for the climb to sky pond. Take something to eat as well. Took us 3 hrs to get to the top. Bring plenty of water and layers of clothes.